[QoL] Show district red path indicator prediction in road and stair menu

I would like to propose that, for road and stair planning, the green-red path indicator should include the prediction when all the blueprint of stair and platform we have layout would finished

I mean, if we put the consecutive stair, it should show that the stair was still in reach of district builder, and so we could plan ahead for the efficiency of road network

Or maybe we could have a toggle for current path and prediction path available in the top right corner